1. Technical Field
The present disclosure relates to window shades, and more particularly, to a cordless fabric venetian window shade assembly. An actuation system of the window shade assembly can include a spring-loaded ratchet system.
2. Background Art
Conventional venetian window shades include those as described in: U.S. Pat. No. 3,384,519 to Froget; FR1,521,488 to Demerson; U.S. Pat. Nos. 5,287,908, 5,313,999, 5,320,154, 5,394,922 and 5,456,304, all assigned to Hunter Douglas, Inc.; and U.S. Pat. No. 5,339,882 to Ren Judkins; U.S. Pat. No. 5,664,613 to Ralph Jelic, now assigned by acquisition to the present applicant's assignee Comfortex Window Fashions; U.S. Pat. No. 5,888,639 assigned to Newell Operating Co.; and U.S. Pat. Nos. 6,024,819; 6,171,424; 6,302,982; 6,377,384; 6,575,222; and 6,634,409 all assigned to the present application's assignee Comfortex Window Fashions, all of which are hereby incorporated by reference.
Conventional fabric venetian window shade assemblies may include a roller that is mounted to a headrail and headrail to the wall or window frame in conventional manner. The fabric venetian window shade itself comprises a first, back fabric facing or layer and a second, front fabric facing or layer. Each fabric facing is usually of high transparency. A plurality of vanes, typically of less translucent fabric, are attached at regular intervals to each fabric facing. The window shade is mounted to the roller such that when the roller is rotated to a first position, the two fabric facings hang from opposite sides of the roller, spaced apart and with the vanes extending between them in an orientation substantially perpendicular to both facings' planes, thus providing maximum view-through. When the roller is rotated in a first direction, it lowers the second, inner fabric facing (which may face internally toward the inside of the room where the shade is hung), and raises the other, first or ‘outer’ facing (which may face externally toward the window). The first effect of such rotation is to close the fabric vanes and bring the vanes and the two facings close together and parallel, to approximate a single quilted fabric. Further rotation of the roller in the same direction can then roll the flattened fabric onto the roller, lifting it from the window area as in a conventional roller shade. Unrolling the shade again reverses this process, with the flattened fabric first lowering to cover the window area, then, with a final partial turn of the roll, separating the first and second facings and tilting the vanes therebetween to provide view-through. Conventionally, this type of shade includes a single, rigid bottom rail connecting the lower, free ends of the facing fabrics. The single bottom rail acts to maintain the facings in smooth, level planes, by tension, and induces the vanes to flex as needed for their tilting by providing additional weight.
Most window shades (e.g., roller, cellular, pleated, or fabric-venetian) can be operated with a cord system, e.g., a cord lock with a pull cord, or a loop cord with a clutch and roller positioned at the top of the assembly. In particular, fabric venetians (sometimes called ‘window shadings’ or ‘window shade assemblies’) such as the Shangri-La™ by Comfortex or Silhouette™ by HunterDouglas, can provide specialty roller shades with multi-layered fabric that includes inner tiltable fabric vanes. These assemblies may include a loop-cord and clutch system to perform a roll rotation which actuates the tiltable vanes once the shade has reached full extension. These clutch systems are typically fitted to the end of the roller, outboard of the fabric width. As a result, the assembly may include an unsightly and undesirable gap located between the edge of the fabric and window opening. This gap may be especially problematic to opaque, light-blocking shade styles because light can travel through the gap between the window and the shade fabric.
Conventional window shade assemblies with cords may also create significant safety hazards. For example, cords and cord loops of conventional window shade assemblies may entangle young children playing in an environment which includes the corded window shade assembly. Many alternative systems without cords and cord loops have been proposed, but most are significantly more expensive than existing window shade assemblies. Actuating the shade with motorized components can also potentially eliminate the presence of cords, in addition to providing other benefits such as remote control or timer-driven deployment, but these alternatives are also more expensive than conventional assemblies. In addition, systems which can fit in place of (i.e., substitute for) the manual clutch and cord-loop most commonly used on large (more costly) shades. The cost of these motors is often as much as that of the shade itself and so these have been restricted to only the most expensive of applications. Further, because the motors fit where clutches would otherwise go, they do not improve the side gap characteristic of the clutch systems.
In conventional roller shades, a spring-balanced ratchet is commonly used. The spring-balanced ratchet can allow the bottom of the shade to be gripped by a user, pulled downward to a length beyond the desired deployment position, and slowly released to set a ratchet that catches the roller against a torsion spring in the roller. The ratchet can be energized by the rotation of the roller when the shade is pulled out. Such an actuator is inexpensive, intuitive to use, and safe. It has not been previously used with fabric venetians because motorized alternatives are installed where existing cords and clutches would be used to pull the shade beyond the desired extension to set (or release) the ratchet. In a conventional roller shade (with simple, single-layer fabric), there is no barrier to providing more fabric length than the window height to enable such over-draw, even when the desired holding position is equal to the entire window height. However, in a fabric venetian shade, this is not possible, because the exact fabric length must be provided to precisely match the window height, so that the final rotation of the roller provides the vane tilting and does not puddle excess fabric on the sill in such configuration. Although it is possible (if the fabric is not too long) to grip the bottom rail and pull down on its back edge (attached to the outer facing) while pushing upward on the inner edge (attached to the inner facing) in order to effect the tilting of the vanes, after the shade fabric is fully extended, such a motion is uncomfortable and unnatural. This motion may be especially inconvenient after merely pulling downward initially for the main deployment. These conventional shades may also continue to include a large gap between the window and the window shade fabric.